Application of Calcium Citrate in the Manufacture of Acid Rennet Cheese Produced from High-Heat-Treated Goat’s Milk from Spring and Autumn Season

The stability of milk proteins is affected by changes in the pH value of milk, the heating temperature, and the addition of calcium compounds or chelating agents, which can cause alterations in calcium distribution. The purpose of this study was to determine the potential of the use of calcium citrate to manufacture fresh acid rennet cheese from high-temperature-pasteurized goat’s milk (90 °C, 15 s) from the spring and autumn season and the effect of the calcium dose used on the physicochemical and organoleptic properties of the cheese. Autumn milk was found to be a richer source of total solids, confirming the effect of the production season on milk quality. The applied doses of calcium did not cause the denaturation of goat milk proteins and allowed pasteurization to take place at 90 °C for 15 s. The addition of calcium citrate resulted in a significant increase in the pH value of milk and cheese compared to the control sample. Adding 15 and 20 mg of Ca 100 g⁻¹ to milk as citrate had the most beneficial effect on increasing protein retention in cheese in both seasons, showing a rise from 1.33% to 2.40%. The production season significantly influenced the cheese yield. The control goat cheese from the autumn season showed a 6.85% higher yield compared to the spring cheese. An increase in cheese yield was also observed as the calcium dose of milk increased. The content of micro- and microelements in cheese was affected by the production season. The addition of calcium citrate to milk resulted in a significant increase in the calcium content of cheese—from 120.83 to 147.45 mg 100 g⁻¹ in the spring season and from 130.66 to 151.21 mg 100 g⁻¹ in the autumn season. Increasing the dose of calcium increased the hardness of cheese samples by 1.37 N in the spring and 0.90 N in the autumn. The organoleptic evaluation showed that adding calcium to milk did not significantly affect the organoleptic characteristics of goat cheese.     

Physicochemical Properties and Functional Characteristics of Ecologically Extracted Shrimp Chitosans with Different Organic Acids during Demineralization Step

The current study aims to develop eco-friendly and economical chitosans with a wide range of applications using organic acids for shrimp shells demineralization. Chitosan samples were extracted from shrimp (Parapenaeus longirostris) shells and the demineralization step was performed with three organic acids (citric, acetic, and lactic) and two mineral acids (hydrochloric and sulfuric). The chitosans were characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), and scanning electron microscopy (SEM). The chitosans’ physicochemical properties were also determined. The characteristic bands and functional groups of the chitosans were identified by FTIR spectra. The chitosans’ crystallinity order was as follows: Ch_HCl > Ch_Citric > Ch_H2SO4 > Ch_Lactic > Ch_Acetic. The chitosans’ morphological characteristics revealed a smooth surface and fibrous structures with pores. Chitosans extracted by organic acids showed the highest extraction yields. Ch_HCl and Ch_Citric had higher degrees of deacetylation values; 83.67% and 81.47%, respectively. The solubility was proportional to the degree of deacetylation. Furthermore, Ch_H2SO4 and Ch_Citric had lower molecular weight values; 149 kDa and 183 kDa, respectively. Organic acids are as effective as mineral acids for shrimp shells demineralization. The developed process opens up possibilities to produce chitin and chitosan in a more eco-friendly way and at a lower cost in many industrial sectors.     

酒西盆地首例湖相"白烟型"喷流岩——热水沉积白云岩的发现及其意义

酒西盆地青西凹陷下沟组中广泛发育的纹层状“白云质泥岩”和“泥岩白云岩”,以其富含铁白云石,钠长石和方沸石等特殊的矿物组分和优越的油气地质条件,引起众多石油地质工作者的重视。以往的研究成果中,认为此两类岩石的成因均与火山作用有关。在该项研究中,依据此两类岩石的空间展布规律与北东向基底断裂的拉张活动密切相关,岩石的矿物组合和结构,构造特征主要显示热水沉积性质,并含有大量重晶石,地开石和再现微量闪锌矿,黄铜矿和方铅矿等特征的热液矿物,认为此两类岩石均属于湖相“白烟型”喷流岩,识别出各以铁白云石、钠长石,重晶石,方沸石和地开石为主的6种热水矿物组合类型,在此基础上,划分出脉状充填型,水爆角砾型,盆地沉积型和区域扩散型4种成因类型的喷流岩,文中首次提出喷流型热水沉积铁白云岩成因类型,探讨了此类白云岩在油气藏勘探与开发工程中的研究意义。     

四川盆地J区块五峰组页岩储层及吸附气特征研究

中国页岩气资源丰富,借助美国页岩气勘探开发经验,中石油、中石化两大石油巨头在四川盆地率先取得突破,中石化在J区块已建成10×108m3/年页岩气产能。为深化认识J区块五峰组页岩储层特征与吸附气特征,通过岩心显微图像、CT扫描和3D FIB图像观察、矿物成分分析、压汞测试、解吸气和吸附气量测量实验及测录井资料进行分析研究。结果表明,页岩代表岩性为灰黑色富含有机质硅质炭质页岩,黏土矿物以伊蒙混层(I/S)为主,脆性矿物以石英、长石为主,含量介于67.5%~85.0%;孔隙度分布在2.0%~7.1%之间,水平渗透率介于0.005~0.545 m D,孔喉半径主要集中分布于4~16 nm;TOC介于1.3%~5.9%,Ro介于2.2%~2.8%;页岩解析气量不低于3.0 m3/t,甲烷饱和吸附体积为2.77 m3/t,总解析气以吸附为主,散失气校正量偏小。研究结果为今后在四川盆地及中上扬子地区寻找页岩气勘探有利区块提供了借鉴。     

藻菌生物成因的矿床类型

生物成矿作用分为生物直接成矿作用和生物间接成矿作用。生物直接成矿作用的标志性结构为生物有机胶体结构,生物间接成矿作用的标志性结构为“矿交代生物”结构。藻菌生物成因的矿床有三类：生物直接成矿作用形成的矿床、生物间接成矿作用形成的矿床、生物直接成矿作用叠加生物间接成矿作用形成的矿床。     

发莱与地木耳的氨基酸和微量元素的初步分析

本文对青海东部地区发菜地木耳的蛋白质、氨基酸、微量元素及无机盐进行了初步分析。结果表明发菜蛋白质含量21.3％。地木耳蛋白质含量18.0％。发菜和地木耳中含有16种氨基酸,其中人体所必需的氨基酸占氨基酸总量的38.6％左右。发菜和地木耳中含有铜锌、锰、钴、钼等多种人体必需的微量元素,铁、钙等营养素含量也十分丰富。     

细集料棱角性对沥青混合料性能的影响

通过分析试验数据，考察了细集料棱角性（FFAA）对沥青混合料沥青用量、体积性质、水稳定性、高温稳定性等重要指标或性能的影响情况。结果表明，FFAA均未与上述指标或性能建立起显著的线性关系。FFAA不适合单独作为评价细集料品质的技术指标，同时也不适合单独采用FFAA来评价细集料对沥青混合料性能影响的情况。     

高分辨率遥感数据在矿产资源开发及动态监测中的应用

介绍了矿产资源开发遥感调查与监测普遍使用的数据信息特点,采用不同时期遥感数据源获取监测目标信息,运用全球定位系统技术确定目标区位,利用地理信息系统技术作为信息处理平台与框架,进行遥感专题数据与规划数据叠加,获得矿山动态监测图,从而进行矿山动态监测、统计与分析,进而对矿产资源的开发、矿山环境的评价,矿山的规划提供服务。     

不同矿物掺合料对轻骨料混凝土抗碳化性能的影响

利用Ⅱ级粉煤灰、超细粉煤灰、磨细矿粉以及钢渣粉等量取代水泥,制备了轻骨料混凝土．并采用加速碳化试验和混凝土孔溶液pH值测试技术,研究了其碳化特性,分析了不同矿物掺合料对轻骨料混凝土抗碳化性能的影响机制．研究结果表明,掺II级粉煤灰和钢渣粉的试样各龄期碳化深度均高于基准样,且不同深度处的混凝土孔溶液pH值也低于基准样;而...     

基于multi-agent的分布式专家系统原理及应用

基于Intemet/Intranet松耦合环境设计分布式选矿专家系统,采用面向agent(智能体)的系统开发方法和multi-agent分布协作求解模式,采用异构异质agent,即agent可建构于广域网、局域网和单处理器紧耦合模式,且求解agent可以是基于符号系统、神经网络、遗传算法等agent的协作.此外,建立了统一的知识库标准,基于关系数据模式表征了传统的规则、框架、语义网络及谓词逻辑等知识表示方法.其中,基于数据库引导及搜索技术实现了正向推理机制及反向推理机制,易于agent之间知识的传输,大大提高了通信效率;基于DCOM技术,以C++构建框架类加速了agent的实现.以矿石可选性预测求解为例,实现了多agent协作求解的仿真系统,较好地验证了所提出的理论模型及框架.